Drill



Nov. 14, 1950 v c. A; SSSSS LL 2 529 788 Patented Nov. 14, 1950 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to novel and useful improvements in detachable bits and means for holding the detachable bits in a drill head.

An object of this invention is to maintain a long bit and a pair of transverse short bits in a drill head by improved means.

Another object of this invention is to provide an improved drill including a head which has at one end thereof a deep recess and a transversely extending shallow recess, the deep recess accommodating guides, which guides have a wedgeshaped opening formed therein in order to accommodate a complementally-shaped cutter.

Another object of this invention is to maintain the plurality of bits and guide members within a drill head by utility of a resilient element.

A further object of this invention is to provide smoothly curved walls in the shallow recess with arcuate or smoothly curved walls on short bits for locking the short bits in the shallow recess.

Ancillary objects and features of novelty will become apparent to those skilled in the art, in following the description of the preferred form of the invention, illustrated in the accompanying drawings, wherein:

Figure 1 is a perspective view of the assembled cutter;

Figure 2 is an exploded perspective view of the elements forming the cutter;

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure l and in the direction of the arrows; and

Figure 4 is a bottom view of the guide in assembled form.

This invention has been developed in order to provide a more efficient tool or cutter for utility in drilling rock and other earth formations of a relatively hard character in nature.

The structure of the invention includes a head In which is somewhat cylindrical in shape as is conventional. The head as well as all of the other portions of the present invention may be made of any suitable material, the cutters or bits being of a metal which is very durable.

The said head is formed at one end with longitudinally tapered cuts generally indicated at l2. There are four of these cuts or cut-outs, increasing in depth as they slope toward the cutting end of the head. These cut-outs are each formed of a pair of walls l4 and [6 which intersect each other at substantially right angles and additional walls l8 and 20, respectively, extending at an angle to the plane of the walls [4 and I6.

A pair of recesses is provided at the end of the head Ill. The first recess is relatively deep and is indicated at 22. This first recess is used for the purpose of accommodating a guide generally indicated at 24 which will be described elsewhere. The second recess is actually formed in two parts 26 and 28, respectively, and the two parts are aligned to form what will be described as the shallow recess. This shallow recess extends across the deep recess 22 at substantially right angles thereto. Both the shallow and the deep recess have arcuate or smoothly curved side walls in order to lock the short cutters 30 and 32, respectively, and the guide 24 in the proper recesses.

The short cutters 30. and 32 extend only the length of the individual cooperating recesses 26 and 28 and these short cutters have smoothly curved side walls (see Figure 1) fitting snugly within the arcuate confining walls of the recesses 26 and 28. By this construction the short bits 30 and 32 may be within the recesses 26 and 28 from the sides thereof but the bits cannot fall from the recesses 26 and 28. In fact, it is contemplated to make the bits 32 and 30 and the recesses 26 and 28 of such sizes that there will be a rather tight fit requiring the bits 30 and 32 to be tapped from the frictional binding fit which results.

Referring now to the guide 24, attention is directed primarily to Figures 2 and 4 wherein there is disclosed a pair of members 34 and 36, respectively. The member 34 has a straight wall 38 and an opposed smoothly curved wall 40. The said wall 40 fits snugly within the arcuate or smoothly curved walls of the recess 22.

The said member 36 has a relatively fiat wall 42 and a smoothly curved wall 44. Of course, the said smoothly curved wall also fits within the confines or restricting walls of the deep recess 22 allowing the resulting guide to be slipped in to the deep recess from the ends of the head only.

In comparison of the two members 34 and 36 it will be seen that the member 36 is thicker than the member 34 in general but one end of the said member 34 has an extending portion 46 (see Figure 4) which fits within a complemental recessed portion of the member 34.

A notch 48 is provided in the member 34 in order to accommodate an enlargement 50 of a resilient member 52. The said enlargement is formed by various bends in a flat metallic element and the enlargement is so configured as to match with the notch 48. A slightly reduced portion is formed along the inner edge of the member 34 and is seen at 54. This slightly reduced portion is obviously to accommodate the shank of the locking member 52. The end of the locking member 52 which is opposite the enlargement 50 is bent as at 56 in order to extend exteriorly of the guide and terminate on the outside of the head 10. For this construction attention is directed primarily to Figure 1.

When the two members 34 and 36 are placed side by side the smooth side 38 of the member 34 cooperates with an inclined side Wall 58 which is spaced therefrom to form an opening or pocket accommodating the cutter bit 60. A construction similar to a dovetail locking means results. However, the bottom walls 62 and 64 of the said wedge-shaped opening are inclined toward a common center in order to seat the similarly shaped bottom walls 66 and 68 of the bit 60.

The bit seated in the wedge-shaped opening of the two assembled portions 34 and 36 forms an element which is maintained in the deep recess 22 through the utility of the locking member 52.

Of course, the cutting edge of each of the bits 60, 32 and 30 are tapered appropriatel in order to perform the cutting operations.

A fluid passage 10 is provided at substantially the center of the head It) and extends longitudinally thereof. A branch passage 12 is substantially U-shaped and formed in the curved sides of the guide 24. This branch passage, of course, cooperates and communicates with the fluid passage 10 in order to conduct a coolant to the cutting edges of the bit while it is operative.

While there has been described and illustrated but a preferred form of the invention it is apparent that variations may be made without departing from the spirit thereof. Accordingly limitation is sought only in accordance with the scope of the following claims.

Having described the invention, what is claimed as new is:

1. For use in drilling rock and other earth formations, a cutter comprising a head block having at one end a longitudinal recess and a relatively deeper longitudinal recess extending transversely of said first-mentioned recess, a pair therebetween, a long bit in said pocket and means for maintaining all of said bits assembled in said head, including a notch and a communicating groove in one of said elements and opening toward the bottom of said deeper recess, a resilient locking member having an enlarged end seated in said notch, and longitudinall tapered cut outs on the side of said head.

2. For use in drilling rock and other earth formations, a cutter comprising a head block having at one end a longitudinal recess and a relatively deeper longitudinal recess extending transversely of said first-mentioned recess, a pair of short bits positioned in said first longitudinal recess and spaced fromeachothena guide positioned in said deeper recess and composed of two elements disposed in side by side relationship, a long bit in said guide and means for maintaining all of said bits assembled in said head, including a notch and a communicating groove in said guide and disposed at the bottom of said deeper recess, a resilient locking member having an enlarged end seated in said notch and engaging the bottom of said deeper recess, said head having a fluid passage therein, and a branch passage in said guide in communication with said fluid passage.

CARL A. SIGNELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 945,735 Hardsocg Jan. 4, 1910 1,178,402 Lindenmuth et a1. Apr. 4, 1916 1,920,035 Stephens July 25, 1933 1,969,040 Sanderson Aug. 7, 1934 2,022,194 Galvin Nov, 26, 1935 2,042,114 McCallum May 26, 1936 2,205,238 Burt June 18, 1940 2,252,745 Williams Aug. 19, 1941 FOREIGN PATENTS Number Country Date 203,039 Great Britain Aug. 30, 1923 

